Improvement in bridges



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TO ALL WHOM I'l MAY CONOERN:

i Be it known thatV I, FREDERICK I-I. SMITH, of Baltimore, Baltimore county, and State of Maryland, have invented a new and useful improvement in Suspension 'lrusses for Bridges, Roofs, tc.; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part oi' this specification, in which- Figure 1 is anelevation of the suspension truss applied to a bridge.

Figure 2 is a ground plan of the same.

Figure 3 is a sectional view.

Similar letters of reference indicate corresponding parts in the several Jfigures.

The natureof my invention consists of a certain arrangement of braces, bars, posts, and straining beams, the whole composing a suspension truss. for supporting roofs, floors, or building bridges, whereby the same strength as in-other suspension trusses is obtained by the use of less material, greater simplicity of construction, by reason of the employment of fewer braces or bars, and less .liability to expansion and contraction from sudden changes of temperature arises, and consequently less danger of injury to the structure.

To enable others skilled in the art to inake and use my invention, I will proceed to describe it with refer ence to the drawings.

a a are the` abntments, piers, or other supports; B B are the straining beams; C1 C2 C3 are the' posts; D D1 D2 D3 D4 D5 D6 are the braces or bars.

The operation of the truss, as applied Vto a bridge is as vfollows: The post C, is supported from the ends of the straining beam, B, by the bars or braces, D D. The posts C1 Cl, are supported from the foot of post, C, by

'the bars or braces, DD, prolongations of DD,.and fromrthe ends of the straining beam, B, by the braces or bars, D2 D. V The posts C2 C2, are supported from the feet of posts, C1 C1, by the braces or bars, D3 D3, prolongations of D D1, and from the ends of the straining beam, B, by the braces' or bars, D* D. The posts C3 O3 are supported from the feet of posts, C2 Cz, by the-braces or bars, DSD, prolongations of D D1 D3, and from the ends of the straining beam by the braces, Ds D5. The upper ends of the posts, 'C Cl C203, are attached to the straining beam, B, by any suitable connections, thus'keeping the latter in place. B'y concentrating all the counter strains in a line, which is a prolongation of the line of the braces or bars, D D, in lieu of carrying them.

from'the foot oi. eaehpost, through separate small`braces or bars, to the ends of the straining beam, great advantages 'are secured, such as simplicity and consequent facility of construction, economy of material, and more security from injury to the structure from sudden changes of temperature, as the mater-iai is disposed in large masses. I

Having thus fully described my inventiomwhat I claim` as new, and desire to secure by LettersiPatent, is

Constructing a suspension truss in such a manner, that all posts other than the center-post C, shall be supported by bars or braces, one of which as D2, extends fromthe foot of the'post C1, to be supported tovan end of the straining beam B, and the other bar or brace D, supporting said post C1, being in a prolongationof the line of thebar or brace D, supporting the center post C, from the opposite end of the straining beam, substan- "ally as described.

To 'the above specification of my improvement in vsuspension trusses for bridges, roofs, 86e., signed this v26th day of April, 1866.

FREDERICK H. SMITH.

. Witnesses:

ALEX. A. C. KLAUcuE', W. F..HALL. 

